HomeMy WebLinkAboutApplication Files_82693_pg0509 Physical Soil Properties—State of Connecticut CT Studios Project,South Windsor,CT
Physical Soil Properties
' This table shows estimates of some physical characteristics and features that affect
soil behavior.These estimates are given for the layers of each soil in the survey
' area.The estimates are based on field observations and on test data for these and
similar soils.
Depth to the upper and lower boundaries of each layer is indicated.
' Particle size is the effective diameter of a soil particle as measured by
sedimentation, sieving, or micrometric methods. Particle sizes are expressed as
classes with specific effective diameter class limits.The broad classes are sand,
silt, and clay,ranging from the larger to the smaller.
Sand as a soil separate consists of mineral soil particles that are 0.05 millimeter to
2 millimeters in diameter.In this table,the estimated sand content of each soil layer
' is given as.a percentage,by weight,of the soil material that is less than 2 millimeters
in diameter.
Silt as a soil separate consists of mineral soil particles that are 0.002 to 0.05
' millimeter in diameter. In this table,the estimated silt content of each soil layer is
given as a percentage,by weight, of the soil material that is less than 2 millimeters
in diameter.
' Clay as a soil separate consists of mineral soil particles that are less than 0.002
millimeter in diameter. In this table,the estimated clay content of each soil layer is
given as a percentage, by weight, of the soil material that is less than 2 millimeters
' in diameter.
The content of sand, silt,-and clay affects the physical behavior of a soil. Particle
size is important for engineering and agronomic interpretations, for determination
of soil hydrologic qualities, and for soil classification.
The amount and kind of clay affect the fertility and physical condition of the soil and
the ability of the soil to adsorb cations and to retain moisture.They influence shrink-
swell potential,saturated hydraulic conductivity (Ksat), plasticity,the ease of soil
dispersion, and other soil properties. The amount and kind of clay in a soil also
affect tillage and earthmoving operations.
' Moist bulk density is the weight of soil (ovendry)per unit volume. Volume is
measured when the soil is at field moisture capacity,that is, the moisture content
at 1/3-or 1/1 0-bar(33kPa or 10kPa)moisture tension.Weight is determined after
the soil is dried-at 105 degrees C. In the table, the estimated moist bulk density of
each soil horizon is expressed in grams per-cubic centimeter of soil material that is
less than 2 millimeters in diameter. Bulk density data are used to compute linear
' extensibility, shrink-swell potential, available water capacity,total pore space,and
other soil properties. The moist bulk density of a soil indicates the pore space
available for water and roots.Depending_on soil texture,a bulk density of more than
1.4 can restrict water storage and root penetration.Moist bulk density is influenced
by texture, kind of clay, content of organic matter,and soil structure.
Saturated hydraulic conductivity(Ksat)refers to the ease with which pores in a
saturated soil transmit water. The estimates in the table are expressed in terms of
micrometers per second.They are based on soil characteristics observed in the
field, particularly structure, porosity,and texture. Saturated hydraulic conductivity
(Ksat)is considered in the design of soil drainage systems and septic tank
absorption fields.
' tl Natural Resources Web Soil Survey 217/2010
Conservation Service National Cooperative Soil Survey Page 1 of 7